The low-temperature rapid equilibrium flash point tester is a key equipment used to determine the flash point of petroleum products, chemicals, etc. under low-temperature conditions (i.e. the low temperature at which the vapor emitted by the liquid mixes with air and instantly ignites when exposed to a fire source). To ensure the accuracy of test results and the safety of equipment, regular inspections (daily checks and maintenance) are required. The following are detailed inspection methods and steps:
1、 Preparation before inspection
Tool Preparation
Standard thermometer (accuracy ± 0.1 ℃, used for calibrating instrument temperature sensors).
Cleaning cloth, dust-free paper, alcohol cotton ball (used for cleaning oil cups, ignition devices, etc.).
Explosion proof gloves and goggles (for operational safety protection).
Inspection Record Form (records equipment status, abnormal situations, and handling measures).
environment check
Ensure stable laboratory temperature (usually requiring 20 ± 5 ℃) and avoid direct sunlight or strong convective winds.
Check if the power supply voltage is stable (meets the rated voltage requirements of the equipment) and if the grounding wire connection is reliable.
Confirm that the experimental table is flat and free from interference from vibration sources.
2、 Appearance and safety inspection
Shell and Structure
Check if the instrument casing is intact, without cracks, deformations, or corrosion.
Confirm that the oil cup, heating device, ignition electrode and other components are securely installed without looseness or displacement.
safety device
Emergency stop button: After pressing, the device should immediately stop heating and ignition, and confirm that the function is normal.
Temperature over limit protection: Simulate over temperature scenarios (such as manually setting above flash point temperature), observe whether the equipment automatically shuts down and alarms.
Gas leakage detection: If gas ignition is used, apply soapy water to the gas pipeline interface and check for the formation of bubbles (no leakage is considered normal).
Electrical safety
Use an insulation resistance tester to test the insulation resistance of the power cord (should be ≥ 1M Ω).
Check the grounding resistance (should be ≤ 4 Ω) to ensure effective anti-static function.
3、 Functional component inspection
1. Temperature control system
Temperature sensor calibration
Immerse the standard thermometer and instrument temperature sensor into a mixture of ice water (0 ℃) or boiling water (100 ℃, with atmospheric pressure compensation) simultaneously.
Compare the temperature displayed by the instrument with the reading of the standard thermometer, and the error should be ≤ ± 1 ℃ (if it exceeds the tolerance, calibration or replacement of the sensor is required).
Heating rate verification
Add an appropriate amount of the test sample (such as n-hexane, with a flash point of about -4 ℃) to the oil cup.
Start the equipment, record the time from room temperature to 20 ℃ before the expected flash point, and calculate the heating rate (which should meet the standard requirements, such as 5-6 ℃/min as specified in GB/T261-2008).
2. Ignition system
Ignition electrode inspection
Clean the surface dirt of the electrode (wipe with an alcohol swab) to ensure there is no carbon or oxide layer.
Adjust the electrode spacing to the standard value (usually 2-4mm, refer to the equipment manual).
Ignition function test
Add a small amount of flammable liquid (such as ethanol) to the oil cup and start the ignition device.
Observe whether the flame is uniform and stable, and the ignition success rate should be ≥ 95% (if ignition fails, check the gas pressure or ignition circuit).
3. Mixing and pneumatic system
Mixing motor inspection
Activate the mixing function and observe whether the mixing blade rotates smoothly without any jamming or abnormal noise.
Measure the stirring speed with a tachometer (which should meet the standard requirements, such as 150 ± 10rpm).
Airway patency
Close the oil cup cap and introduce low-pressure air (such as 0.1MPa) into the air path.
Immerse the end of the air path into water and observe if there are continuous bubbles generated (no bubbles indicate blocked air path and need to be cleaned or replaced filter element).
4. Display and Recording System
Screen inspection
Confirm that parameters such as temperature, time, heating rate, etc. are displayed clearly without missing pens or garbled text.
Test the data storage function to ensure that historical records are searchable and not lost.
printer test
Print the test report and check that the printed content is complete (including sample name, flash point value, test date, etc.).
Confirm that there is sufficient printing paper and that there are no paper jams or ink smudges on the print head.
4、 Performance verification testing
Standard sample testing
Use standard samples with known flash points (such as n-heptane, flash point -4 ℃; isooctane, flash point -12 ℃) for testing.
Repeat the test 3 times and calculate the repeatability of the flash point value (standard deviation should be ≤ 2 ℃).
comparative testing
Simultaneously test the same sample with another calibrated flash point tester and compare the differences in results (should be ≤ 3 ℃, otherwise the source of equipment error needs to be investigated).
5、 Post inspection processing
Cleaning and Maintenance
Empty the oil cup, clean the residual sample with alcohol, air dry and return to its original position.
Wipe the instrument casing with a dry cloth and avoid using corrosive cleaning agents.
Record and Report
Fill out the inspection record form, indicate the equipment status (normal/abnormal) and the corresponding handling measures.
If serious malfunctions are found (such as temperature loss of control or ignition failure), immediately stop the equipment and contact maintenance.
Calibration cycle recommendation
Daily inspection: Conduct a visual and basic functional check before each use.
Regular calibration: Comprehensive calibration (including temperature, ignition, stirring, and other systems) is conducted by a professional organization every 6 months.
6、 Safety precautions
Wear explosion-proof gloves and goggles during operation to avoid high temperature burns or sample splashes.
Do not open the oil cup cover or touch the heating components during device operation.
Abandoned samples must be recycled according to the hazardous chemical handling regulations, and dumping at will is strictly prohibited.
If the equipment is not used for a long time, the power should be disconnected and stored in a dry and ventilated place.
Through systematic inspection methods, the service life of low-temperature rapid equilibrium flash point measuring instruments can be effectively extended, ensuring the reliability of test data and providing accurate technical support for fields such as petrochemicals and safety testing.